Pinatubo?
"As a result, from 1992 to 1993,
large parts of the planet cooled as much as 0.7 degrees Fahrenheit (0.4 degrees Celsius)"
https://www.livescience.com/14513-pinatubo-volcano-future-climate-change-eruption.htmlSo
parts of the planet cooled 0.4 degrees.
Versus your claim, of 1 degree of cooling, globally, for Pinatubo?
The effect of Pinatubo is 0.4 degrees of cooling to parts of the globe, so clearly less than the 0.4 degrees of cooling to the global overall.
So maybe around 0.2 degrees, similar to Krakatoa ...
Which is consistent with the NASA 0.19 degree drop
https://climate.nasa.gov/vital-signs/global-temperature/Pinatubo was a comparable sized VEI 6 erruption to Krakatoa
"Volcanologists rank large eruptions as: Level 5) like the ones at Mount St. Helens in 1980 and Mt. Vesuvius in the A.D. 1st century that occur every 10 years and release less than a hundred cubic kilometers of material; Level 6) like the ones at Mount Pinatubo in 1991 and Krakatau in 1883 that occur every 100 years and release more than a hundred cubic kilometers of material;"
http://factsanddetails.com/world/cat51/sub323/item2209.htmlAll rough comparisons, and other factors like La Nina and El Nino would also need to be factored in.
But your numbers and assessment look well out. NASA looks fine.
